Thanks for the link and advice...but I went ahead and ordered a second hand subframe complete with arms etc., as it was cheaper than two new upper arms.
Only problem is I've checked out 4 local garages already, and none of them want to do the work! Too many problems with taking out the old subframe they reckon
. I have found one who says he'll do it now, so fingers crossed it goes smoothly, as £50+ an hour for mechanic's time is no joke...